Adjusting device for lapping tools



` Dec. 17, 1946. A.` M. DRAKE ADJUSTING DEVICE FOR LAPPING TOLS :ssheets-sheet'l Filed NOV. 18, 1944 INVENTOR.

ZAHZE Dec. l?, E946.'

A. M. BRAKE ADJUSTING DEVICE FOR LAPPING TOOLS Filed Nov. 18, 1944 3SheetsjSheet 2 fig@- 3 Sheets-Sheet 3 QM bv mm,

vIllu l illllllllllllllidl H nwwmwunmmmuuuwnlununml| IN VEN T 0R.

M/w'e Dec. 17, 1946. 'A M, DRAKE ADJUSTING DEVICE FOR LAPPING TOOLSFiled Nov. 1-8, 1944 Patented Dec. 17, 1946 2,412,721 ADJU STIN G DEVICEFOR LAPPING TOOLS Alden M. Drake, West Hartford, Conn.,

to Niles-Bement-Pond Company,

assignor West Hartford, Conn., a corporation of New Jersey ApplicationNovember 18, 1944, Serial No. 564,155

6 Claims.

This invention relates to lapping machines and particularly to a machinefor lapping internal cylindrical surfaces to precision dimensions.

An object of the invention is to provide improved lap adjusting means ina machine for automatically actuating a work piece being lapped over thesurface of a lapping tool which may be rotated simultaneously withreciprocations of the work piece.

Primarily it is an object of the present invention to provide impactmeans manually applied under controllable conditions to slightly varythe effective diameter of the lapping tool during the lapping operation.

A feature of importance is that the impact means are operative in onedirection to increase the effective diameter of the lapping surface andin the opposite direction to decrease the effective diameter.

Another feature of advantage is that the two impact means areindependently actuated and may be adjusted individually over wideranges, so that but one or both impact means may be `enflployed to anyextent that may be necessary to make the desired adjustment.

With the above and other objects in view the invention includes thefeatures of construction and operation set forth in the followingspecification and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part of thisspecification, I have shown the invention embodied in a hole lappingmachine for rolls of small size used in dimension gages but it will beunderstood that the invention can be otherwise embodied and that thedrawings are not to be construed as defining or limiting the scope ofthe invention, the claims appended to this specication being relied uponfor that purpose.

In the drawings:

Figure 1 is a vertical sectional view takenlongitudinally through theprincipal parts of a machine embodying one form of the presentinvention.

Fig. 2 is a longitudinal sectional view in elevation showing one form ofimpact means for forcing a lap axially along its arbor to slightlyvincrease the size of the lapping surface during the lapping operation.

Fig. 3 is a detail view of parts shown in Fig. 2 taken from below.

Fig, iis a longitudinal view of a lap on its arbor showing one of theimpact members in retracted position.

Fig. 5 is a cross sectional view of the arbor and lap taken on the planeof line 5-5 of Fig. 4.

Fig. G is a longitudinal view partly in section of another iorm ofimpact means.

Fig. 7 is an end elevation of the impact means shown in Fig. 6.

Fig. 8 is a longitudinal sectional view of a part oi the mechanism shownin Fig. 6, the section beingtaken on the plane of line 8 8 in Fig. 6.

Fig. 9 is a horizontal sectional View of parts shown in Fig. 6, thesection being taken on the plane of line 9-3 in Fig. 6.

Fig. 1G is a sectional View of of a. part of the impact mechanism forreducing the size of the lapping member, the section being taken on theplane of line lll-lli in Fig. 7, and

Fig. l1 is a sectional view of parts shown in Fig. 7, the section `beingtaken on the plane of line i-l in Fig. 10.

In the above mentioned drawings there have been shown two embodiments ofthe invention which are now deemed preferable, but it is to beunderstood that changes and modifications may be made within the scopeof the appended claims without departing from the spirit of theinvention.

In lapping rotatably mounted members for gages it is essential that theholes by means of which they are mounted ce of uniform diameter from endto end and without bell-mounting. The rolls must fit their arborsclosely and evenly from end to end so that they will not tilt during usebut will rotate smoothly on their arbors about a Xed axis. lieretoforeprecision lapping of internal cylindrical surfaces has, for the mostpart, Abeen done manually, the work piece being held manually inposition upon a rotating lappingA tool on a suitabie spindle and slowlyreciprocated back and forth during rotation of the spindle vand lappingtool. The lap usually comprised a split cast iron sleeve charged withabrasive and fitting tightly but resiliently over a slightly taperedarbor secured to the spindle. To expand the lapping surface the sleevehaving the lapping surface was forced axially along the taered arbor.

The present invention relates particularly to impact `means for forcingthe expansible lap predetermined slieht amounts axially during thelapping operation to slightly increase its diameter, other impact meansalso being provided to move the lapping tool in the opposite directionYuary 29, 1944, of which the on its arbor to reduce slightly its lappingdiameter.

Briefly, and in its preferred aspect, the invention may include thefollowing principal parts: First, a spindle adapted to be rotated by anyappropriate means and having means at its forward end to mount an arborextending axially from the spindle; second, a, plunger aligned with thelapping spindle and adapted to be resiliently retracted and released forforward movement to strike the end of the lapping tool so that theposition of the lapping tool on its spindle may be adjusted axially toslightly increase its diameter; and third, a second plunger mounted forrapid forward movement and adapted to engage a member bearing againstthe opposite end of the lapping tool and move it axially to slightlydecrease its diameter.

Referring more in detail to rthe figures of the drawings and first toFig. l, I provide a spindle I adapted to be driven by a bevel gear I Ion ashort shaft I2 in alinement with the spindle I9 and which in turnmay be driven through any suitable connections such as a driving bevelgear I3 connected by means no-t shown to a suitable source of power. 'Atthe forward end of the spindle is an arbor I9 extending axiallytherefrom and preferably detachably mounted thereon.

Above the spindle Ill is a reciprocated member I4 on which is mounted awork holder SI within which the work piece being lapped is mounted forreciprocatory movement along the arbor I9 during the lapping operation.

The above members are or may be similar in every way to correspondingmembers in my copending application Serial No. 520,257, filed Janpresentapplication is a continuation in part.

The lapping member 29 may be similar to the member shown in the abovereferred to application and formed of cas-t iron or other metal slottedlongitudinally throughout its length and bored to fit a slight :taperedportion of the arbor I9.

In order to adjust the position of the lapping member or sleeve 2l) uponits arbor I9 to vary its effective diameter as required during thelapping operation, impact means are provided which may be actuatedmanually todeliver a carefully regulated blow upon an end face of thesplit sleeve forming the lapping tool 29 to force this member axially onits arbor I9 a slight but predetermined distance depending upon theforce of the blow; Figs. 1, 2 and 3 show one form of impact mechanismacting in one direction only to increase the diameter of the lappingsurface of the lapping tool. To effect this impact adjustmenlt of thelap 29, a bracket ZI is mounted upon the base of the machine having aplunger 22 therein disposed accurately in alinement with the spindle Iiiand arbor I9. This plunger 22 is mounted within the retractible memberwithin the bracket 2l and is normally forced toward the lapping spindleby a helical spring 2d. Manually retracting this member 23 compressesthe spring 24, then, upon. release of the member 23 the plunger22 willbe yforced forwardly and its end face will be brought into contact withand force the lapping rtool 20 axially along its arbor I9. To adjust theaxial position of the plunger 22 so that its end face will strike theend of lapping sleeve 29, the plunger 22 may be threaded -throughout themajor portion of its length, the threads of which engage a retractibledetent 25 mounted within the bracket 2|. The plunger and 8.

22 may, therefore, by rotation, be accurately adjusted so that whenforced forward it will strike the lap 29. Also, by disengaging thedetent 25, the plunger 22 may be quickly moved any distance in eitherdirection. The forward or striking end of this plunger 22 may beprovided with an adapter 29 rotatable within the plunger 22 and recessedto t over the end of the lapping arbor I9 and directly engage the frontface of the sleeve 23 forming the lap.

In order to control the force of the blow ei fected by this plunger 22,means are provided to adjust the pressure of the helical spring 24. Aswill be seen in Fig. 2, the helical spring is housed in the bracket 2lwithin a suitablev recess. The forward end of the spring 24 bearsagainst the head of a bolt 2l extending thro-ugh the bracket 2l andthrough a portion of the retractible member 23. The outer end of thisbolt 21 is threaded and is engaged by a suitable manual adjusting nut2S. By rotation of this nut 28 the pressure of the helical spring 24forcing the retractible member 23 toward its forward position may bewidely varied.V In order to effect the delivery of face of `lap 23` ahand lever 29 is provided having a projection `or latch 30 adapted toengage a depending pontion of the retractible member 23 so that byoscillation of this handle 29 the projection will be disengaged from thedepending portion of the retractible member 23 after a predeterminedretractive movement. This will release the retractible member 23 forforward movement under the adjusted pressure of the helical spring 24.To adjust the plunger 22 so that it will Contact the end face of thelapping tool and advance this tool a predetermined distance whenreleased, it is only necessary to rotate the plunger 22 within theretractible member 23.

Figs. 6 to 11 show another form of impact means for action upon thelapping member 20 to move it axially along its arbor in either directionto increase or decrease the effective diameter of its lapping surface.

In the mechanism shown in Fig. 6 et seq. for advancing the lap 2i) in adirection to increase its effective diameter, a construction veryVsimilar to that shown in Fig. 2 is employed. This mechanism has aretractibleplunger 32 which may be adjusted axially toward or from thelapping tool 29 by means of a threaded portion thereon and the impactmay be adjusted by a helical spring 34 adjusted by a manually rotatablenut 35. The blow may be delivered by depressing a plunger 36 to releasea latch 31 from a member 39 within which the plunger 32 is mountedattached to the plunger 32 to force the plunger toward the lap. Theabove described mechanism is mounted on a fixed .bracket 38 and will-beclear by an examination of Figs. 6, 7

In order to deliver a blow in a direction to move the lapping tool 2i)along its arbor I9 in a direction to reduce its effective diameter, thefollowing, mechanism is employed. Withinthe bracket 38 supporting theplunger 32 for increasing the diameter of the .lap is a second plunger40 which may be retracted manually Y against the pressure of a coilspring 4I andreleased by simply releasing the handle. The pressureeffected by the spring I may be regulated by a threaded nut 52, rotationof which varies the compression ofthe spring 4l to any predetermineddegree. The inner or active end of the plunger 4l) is' within strikingdistance of an the blow by plunger r22 against the end,

arm 43 pivoted substantially at its central position on a horizontalaxis 44 so that it may swing in a vertical plane. The plunger 40 strikesthe lower end of this vertical pivotal arm 43'. and at its upper end isprovided with a member 45 adapted to strike against an abutment member46 engaging against the inner end face of the sleeve 20 forming thelapping tool. A spring 41, as shown in Figs. '7, 10 and 11, serves toretain the arm 43 in its vertical striking position and a pendulum 48supported within a horizontal bearing in the bracket 38 at the upperportion of the arm 43 serves to hold in vertical position the head 45engageable against the striking mem ber 46 when the arm 43 is oscillatedby the plunger 40.

What I claim is:

1. An adjusting device for lapping tools of the expansible sleeve type,said device comprising a striking plunger mounted in alinement with saidsleeve and movable into contact with an end face of said sleeve whilemounted on its spindle, means normally forcing said plunger in onedirection, retracting means for said plunger, and means to release saidplunger from a retracted position, whereby said plunger may strike andforce said sleeve axially on its spindle.

2. An adjusting device for lapping tools oi the expansible sleeve type,said device comprising a striking plunger mounted in alinement with saidsleeve and movable into contact with an end face of said sleeve whilemounted on its spindle, means normally forcing said plunger in onedirection, retracting means for said plunger, and means to release saidretracting means from a predetermined retracted position, whereby saidplunger may strike a regulatable blowv and force said sleeve axially onits spindle.

3. An adjusting device for lapping tools of the expansible sleeve type,said device comprising a striking plunger mounted in alinement with saidsleeve and movable into contact with an end face of said sleeve whilemounted on its spindle, means normally forcing said plunger toward itsstriking position, retracting means for said plunger, and means torelease said retracting means from a predetermined retracted positionwhereby said plunger may strike and'i'orce said sleeve axially on itsspindle.

4. An adjusting device for lapping tools of the expansible sleeve type,said device comprising a striking plunger mounted in alinement with said5. An adjusting device for lapping tools of the expansible sleeve type,said device comprising a striking plunger mounted in alinement with saidsleeve and movable into contact with. an end face of said sleeve whilemounted on its spindle, and a second plunger mounted parallelly to saidrst plunger to actuate a pivotal arm into position to strike the sleeveat its opposite end, means normally forcing said plungers in onedirection, separate retracting means for said plungers, and means toindividually release said retracting means from predetermined retractedpositions whereby said plungers may Aforce said sleeve axially on itsspindle in either direction.

6. An adjusting device for lapping tools of the expansible sleeve type,Said device comprising parallel striking plungers, one of which is mounted in alinement with said sleeve and movable respectively into contactwith an end face of said sleeve while mounted on its spindle, meansnormally forcing said plungers in one direction, individual retractingmeans for said plungers. and means to release one of said retractingmeans from a retracted position whereby its plunger may strike and forcesaid sleeve axially on its spindle in a direction to enlarge thediameter of said sleeve, and means to release the other of saidretracting means from a retracted position and force its plunger in adirection to engage a striker and oscillate said striker against theopposite end of said sleeve.

ALDEN M. BRAKE.

